An air battery is a battery having oxygen as an active material. The air battery has air holes for intake of air and electrodes (air electrodes) that react with oxygen in the received air. Such an air battery generates electricity using oxygen in the air as the active material.
A thin-film is used to selectively extract oxygen from air drawn in through the air holes. Patent document 1 proposes providing a polysiloxane thin-film between the air holes and the air electrodes, while Patent document 2 proposes providing a polyimide thin-film.